Continuity: In episode 54 "Honor" at the end of the episode when showing the flashback of Carl's death, when he is laying on the ground already dead his arm changes position from being bent with his hand at his shoulder, to being straight by his side.

Revealing: In the Season Five opener "Thrill Kill," when Dylan is being led out of jail, you can see palm trees in the background behind him. This reveals that the scene was filmed in Los Angeles, not Philadelphia.

Factual error: In the episode "8 years" the opening scene is identified as taking place in 1980, yet the characters are singing along to "No Surrender" which wasn't released until 1984.

Factual error: In the 5th episode of season 5, "Thick as Thieves", look at the area by the door when we see Margot and Spencer in the hotel room in 1989. The light switch is a flat "Decora" switch, and above the door handle is a black box that houses electronics for a "card key" system. The light switch was not introduced until the 1990s, and while the card key system was introduced in 1985, only very expensive hotels afforded the conversion costs - and the hotel they're at isn't exactly the Hilton.

Factual error: In episode 2-21: "Creatures of the Night," Mike and Kelly are at the theater watching "Rocky Horror Picture Show" in 1977, talking during the song "Sweet Transvestite." After the line "satanic mechanic" and the audience callback "S and M.", which is only about two thirds of the way into the song, the music suddenly crescendos and ends, to be replaced by the song "Touch-a Toucha-a Touch Me," which occurs several scenes further into the movie.

Factual error: In episode 55 "The Perfect Day" they show a 1965 flashback of a blue Philadelphia Police car. The Philadelphia police didn't go to the blue cars until 1973 when Mayor Frank Rizzo saw that New York went to the blue cars and liked the color. Before that the cars were red.

Factual error: In episode 55 "The Perfect Day" they show the side of a 1965 Philadelphia Police car. The gold shield on the door was not used until 1968.

Continuity: In the episode "Sandhogs" When they are flashing back on "Bobby" in 1948 The actor has 2 piercings in his left ear. Men wouldn't have pierced ears in 1948.

Continuity: In Episode 90, "Torn" from Season 4 (4/8/07), at the end of the episode, when Elizabeth Stone is arguing with her daughter at the top of the stairs, her shawl goes from around her arms, to across her back, to completely gone several times from shot to shot.